A force of 10 N pulls a 2 kg mass across a horizontal table...?

Question

The acceleration is 4 m/s^2. What is the coefficient of friction?

The answer on the key is 0.102. But I don't know how to get there.

Answer 1

F(net) = m * a = 4 * 2 = 6 N

So, of the 10 N of force, 4 N are absorbed by friction
F(friction) = normal force * mu
normal force = m * g
F = m * g * mu
4 = 2 * 9.8 * mu
Coefficien of friction = 0.204